One vertex per element, one color per generator, with an edge from x to x·s.
(2,5)(3,6)(7,8)(9,10,14,18,15,19,13,27)(11,16,21,32,22,33,28,31)(12,23,25,35,26,17,29,36)(20,30,38,39,24,34,37,40)(1,2,6,8,4,7,3,5)(9,11,13,21,15,22,14,28)(10,16,18,31,19,33,27,32)(12,24,25,38,26,20,29,37)(17,34,35,40,23,30,36,39)(2,7)(5,8)(9,12)(10,17)(11,20)(13,25)(14,29)(15,26)(16,30)(18,35)(19,23)(21,37)(22,24)(27,36)(28,38)(31,39)(32,40)(33,34) involution — undirected(9,13,15,14)(10,18,19,27)(11,21,22,28)(12,25,26,29)(16,31,33,32)(17,35,23,36)(20,37,24,38)(30,39,34,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.